El fantasma del baile (Tessa Soul, 1)

When Tessa Soul arrives at Baxter Hall in England, fleeing the war, she thinks she can finally find some peace and quiet. She's wrong. Baxter Hall is haunted, and one of the ghosts desperately needs her help. Lavender, a spirited young ghost, is tired of wandering the halls; she just wants to leave and be reunited with her mother. To find out how to help her, Tessa and her new friend, Angus, begin their investigation. The answers lie in the Baxter family's old diaries and a fabulous diamond tiara, worn only on the night of the grand summer ball. Will Tessa and Angus arrive in time to save Lavender?